Effect of low power laser in biomodulation of cultured osteoblastic cells of Wistar rats

Abstract Purpose: To analyze aspects of the biomodulating effect of light in biological tissues, bone cells from surgical explants of the femur of rats were irradiated with low intensity laser. Methods: Bone cells were cultured and irradiated with LASER light (GaAlAs). Growth, cell viability, mineralized matrix formation, total protein dosage, immunostimulatory properties, cytochemical analysis, gene expression of bone proteins were examined using live cell imaging and cell counting by colorimetric assay. The gene expression of: alkaline phosphatase (ALP), type 1 collagen, osteocalcin and osteopontin through the real-time polymerase chain reaction. Results: At 8 days, the viability of the irradiated culture was 82.3% and 72.4% in non-irradiated cells. At 18 days, the cellular viability (with laser) was 77.42% and 47.62% without laser. At 8 days, the total protein concentration was 21.622 mg / mol in the irradiated group and 16, 604 mg / mol in the non-irradiated group and at 18 days the concentration was 37.25 mg / mol in the irradiated group and 24, 95 mg / mol in the non-irradiated group. Conclusion: The laser interfered in the histochemical reaction, cell viability, matrix mineralization, and maintained the cellular expression of proteins

MicroRNA-153-3p enhances cell radiosensitivity by targeting BCL2 in human glioma

BACKGROUND: Glioma is the most prevalent malignant tumor in human central nervous systems. Recently, the development of resistance to radiotherapy in glioma patients markedly vitiates the therapy outcome. MiR-153-3p has been reported to be closely correlated with tumor progression, but its effect and molecular mechanism underlying radioresistance remains unclear in glioma. METHODS: The expression of miR-153-3p was determined in radioresistant glioma clinical specimens as well as glioma cell lines exposed to irradiation (IR) using quantitative real-time PCR. Cell viability, proliferation and apoptosis were then evaluated by MTT assay, colony formation assay, Flow cytometry analysis and caspase-3 activity assay in glioma cells (U87 and U251). Tumor forming was evaluated by nude mice model in vivo. TUNEL staining was used to detect cell apoptosis in nude mice model. The target genes of miR-153-3p were predicted and validated using integrated bioinformatics analysis and a luciferase reporter assay. RESULTS: Here, we found that miR-153-3p was down-regulated in radioresistant glioma clinical specimens as well as glioma cell lines (U87 and U251) exposed to IR. Enhanced expression of miR-153-3p promoted the radiosensitivity, promoted apoptosis and elevated caspase-3 activity in glioma cells in vitro, as well as the radiosensitivity in U251 cell mouse xenografs in vivo. Mechanically, B cell lymphoma-2 gene (BCL2) was identified as the direct and functional target of miR-153-3p. Moreover, restoration of BCL2 expression reversed miR-153-3p-induced increase of radiosensitivity, apoptosis and caspase-3 activity in U251 cells in vitro. In addition, clinical data indicated that the expression of miR-153-3p was significantly negatively associated with BCL2 in radioresistance of glioma samples. CONCLUSIONS: Our findings suggest that miR-153-3p is a potential target to enhance the effect of radiosensitivity on glioma cells, thus representing a new potential therapeutic target for glioma.

Analysis of radioprotection and antimutagenic effects of Ilex paraguariensis infusion and its component rutin

DNA repair pathways, cell cycle checkpoints, and redox protection systems are essential factors for securing genomic stability. The aim of the present study was to analyze the effect of Ilex paraguariensis (Ip) infusion and one of its polyphenolic components rutin on cellular and molecular damage induced by ionizing radiation. Ip is a beverage drank by most inhabitants of Argentina, Paraguay, Southern Brazil, and Uruguay. The yeast Saccharomyces cerevisiae (SC7Klys 2-3) was used as the eukaryotic model. Exponentially growing cells were exposed to gamma rays (γ) in the presence or absence of Ip or rutin. The concentrations used simulated those found in the habitual infusion. Surviving fractions, mutation frequency, and DNA double-strand breaks (DSB) were determined after treatments. A significant increase in surviving fractions after gamma irradiation was observed following combined exposure to γ+R, or γ+Ip. Upon these concomitant treatments, mutation and DSB frequency decreased significantly. In the mutant strain deficient in MEC1, a significant increase in γ sensitivity and a low effect of rutin on γ-induced chromosomal fragmentation was observed. Results were interpreted in the framework of a model of interaction between radiation-induced free radicals, DNA repair pathways, and checkpoint controls, where the DNA damage that induced activation of MEC1 nodal point of the network could be modulated by Ip components including rutin. Furthermore, ionizing radiation-induced redox cascades can be interrupted by rutin potential and other protectors contained in Ip.

Low-intensity pulsed ultrasound promotes proliferation and migration of HaCaT keratinocytes through the PI3K/AKT and JNK pathways

Although the effects of low-intensity pulsed ultrasound (LIPUS) on diverse cell types have been fully studied, the functional role of LIPUS in keratinocytes remains poorly understood. This study aimed to investigate the effects of LIPUS on proliferation and migration of HaCaT cells as well as the regulatory mechanisms associated with signaling pathways. Human HaCaT cells were exposed or not to LIPUS, and cell proliferation and migration were measured by BrdU incorporation assay and Transwell assay, respectively. Expression of proteins associated with proliferation and migration was evaluated by western blot analysis. Expression of key kinases in the PI3K/AKT and JNK pathways was also evaluated by western blot analysis. Effects of LIPUS on the PI3K/AKT and JNK pathways, and whether LIPUS affected HaCaT cells via these two pathways were finally explored. When the parameter of LIPUS (number of cycles) was set at 300, cell viability was the highest after LIPUS stimulation. We then found that the percentage of BrdU positive cells was enhanced by LIPUS, along with up-regulation of cyclinD1, CDK6, CDK4, and VEGF. LIPUS promoted migration, as well as up-regulation of MMP-2 and MMP-9. Phosphorylation levels of key kinases in the PI3K/AKT and JNK pathways were increased by LIPUS. Inhibition of either PI3K/AKT pathway or JNK pathway attenuated effects of LIPUS on HaCaT cells, and co-inhibition of these two pathways showed augmented effects. LIPUS promoted proliferation and migration of HaCaT cells through activating the PI3K/AKT and JNK pathways.

Low-level laser irradiation promotes proliferation of cryopreserved adipose-derived stem cells / Laser de baixa intensidade promove proliferação de células-tronco derivadas de tecido adiposo criopreservadas

ABSTRACT Objective To evaluate the effect of low-level laser irradiation on proliferation and viability of murine adipose-derived stem cells previously submitted to cryopreservation. Methods Adipose-derived stem cells were isolated from inguinal fat pads of three mice, submitted to cryopreservation in fetal bovine serum with 10% dimethylsulfoxide for 30 days and then thawed and maintained in normal culture conditions. Culture cells were either irradiated or not (control) with an InGaAIP diode laser at zero and 48 hours, using two different energy densities (0.5 and 1.0J/cm2). Cell proliferation was evaluated by trypan blue exclusion method and MTT assay at intervals of zero, 24, 48, and 72 hours after the first laser application. Cell viability and apoptosis of previously cryopreserved cells submitted to laser therapy were evaluated by flow cytometry. Results The Irradiated Groups (0.5 and 1.0J/cm2) showed an increased cell proliferation (p<0.05) when compared to the Control Group, however no significant difference between the two energy densities was observed. Flow cytometry revealed a percentage of viable cells higher than 99% in all groups. Conclusion Low-level laser irradiation has stimulatory effects on the proliferation of adipose-derived stem cells previously submitted to cryopreservation.

RESUMO Objetivo Avaliar o efeito do laser de baixa intensidade na proliferação e na viabilidade de células-tronco derivadas de tecido adiposo murinas previamente submetidas à criopreservação. Métodos Células-tronco derivadas de tecido adiposo foram isoladas da região inguinal de três camundongos, submetidas à criopreservação em soro fetal bovino com 10% de dimetilsulfóxido por 30 dias e, depois, descongeladas e mantidas em condições normais de cultivo. As células cultivadas foram irradiadas ou não (controle) com um laser de diodo InGaAIP nos intervalos de zero e 48 horas, utilizando duas densidades de energia diferentes (0,5 e 1,0J/cm2). A proliferação celular foi avaliada pelo método de exclusão de azul de tripan e ensaio MTT, nos intervalos de zero, 24, 48 e 72 horas após a primeira aplicação do laser. A viabilidade celular e a apoptose das células previamente criopreservadas submetidas à laserterapia foram avaliadas por citometria de fluxo. Resultados Os Grupos Irradiados (0,5 e 1,0J/cm2) apresentaram aumento da proliferação celular (p<0,05) quando comparados ao Grupos Controle, porém não foi observada diferença significativa entre as duas densidades de energia. A citometria de fluxo revelou percentagem de células viáveis superior a 99% em todos os grupos. Conclusão O laser de baixa intensidade tem efeitos estimuladores sobre a proliferação de células-tronco derivadas de tecido adiposo previamente submetidas à criopreservação.

Cytotoxicity and cytokine expression induced by silorane and methacrylate-based composite resins

ABSTRACT The successful use of composite resins in Dentistry depends on physicochemical properties, but also on the biological compatibility of resins, because of the close association between pulp and dentin. Objective The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. Material and Methods Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc test (α=0.05). Results KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p<0.05) after 24 h of incubation. KaloreTM stimulated the early production of TNF-α in comparison with control (p<0.05), whereas FiltekTM Silorane did not affect TNF-α levels after 6 and 12 h (p>0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). Conclusions KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane.

Effects of low-level laser therapy on stem cells from human exfoliated deciduous teeth

ABSTRACT Low-Level Laser Therapy stimulates the proliferation of a variety of types of cells. However, very little is known about its effect on stem cells from human exfoliated deciduous teeth (SHED). Objective This study aimed to evaluate the influence of different laser therapy energy densities on SHED viability and proliferation. Material and Methods SHED were irradiated according to the groups: I (1.2 J/cm2 - 0.5 mW – 10 s), II (2.5 J/cm2 – 10 mW – 10 s), III (3.7 J/cm2 – 15 mW – 10 s), IV (5.0 J/cm2 – 20 mW – 10 s), V (6.2 J/cm2 – 25 mW – 10 s), and VI (not irradiated – control group). Cell viability was assessed 6 and 24 h after irradiation measuring the mitochondrial activity and using the Crystal Violet assay. Cell proliferation was assessed after 24, 48, and 72 h of irradiation by SRB assay. Results MTT assay demonstrated differences from 6 to 24 hours after irradiation. After 24 h, groups I and IV showed higher absorbance values than those of control group. Crystal Violet assay showed statistically differences in the absorbance rate from 6 to 24 h after irradiation for groups III and VI. At 24 h after irradiation, Group III absorbance rate was greater than that of groups I, II, and IV. Group VI absorbance rate was greater than that of groups I and IV. SRB assay showed that the group I had higher rates than those of groups II, III, V, and VI, at 24 h after irradiation. After 48 h, group I exhibited the greatest cell proliferation rate followed by groups III, V, and VI. After 72 h, group III exhibited the lowest cell proliferation rate than those of groups II, IV, and V. Conclusions The Low-Level Laser Therapy energy densities used in this study did not cause loss of cell viability and stimulated SHED proliferation within the parameters described in this study.

The effects of riboflavin and ultraviolet light on keratocytes cultured in vitro / Avaliação do efeito da riboflavina e luz ultravioleta sobre os ceratócitos in vitro

ABSTRACT Purpose: To culture quiescent human keratocytes and evaluate the effects of ultraviolet light and riboflavin on human corneal keratocytes in vitro. Methods: Keratocytes were obtained from remaining corneoscleral ring donor corneas previously used in corneal transplant surgeries and cultured in DMEM/F12 with 2% FBS until confluence. Characterization of cultured cells was performed by immunofluorescence analysis for anti-cytokeratin-3, anti-Thy-1, anti-α-smooth muscle actin, and anti-lumican. Immunofluorescence was performed before and after treatment of cultured cells with either ultraviolet light or riboflavin. Corneal stromal cells were covered with collagen (200 µL or 500 µL) and 0.1% riboflavin, and then exposed to ultraviolet light at 370 nm for 30 minutes. After 24 hours, cytotoxicity was determined using MTT colorimetric assays, whereas cell viability was assessed using Hoechst 33342 and propidium iodide. Results: Cell cultures achieved confluence in approximately 20 days. Expression of the lumican was high, whereas no expression of CK3, Thy-1, and α-SMA was observed. After crosslinking, MTT colorimetric assays demonstrated a low toxicity rate, whereas Hoechst 33342/propidium iodide staining demonstrated a low rate of apoptosis and necrosis, respectively, in all collagen-treatment groups. Conclusion: Keratocytes can be successfully cultured in vitro and characterized by immunofluorescence using lumican. MTT colorimetric assays, and Hoechst 33342, and propidium iodide staining demonstrated a higher rate of cell death in cells cultured without collagen, indicating collagen protects keratocytes from the cytotoxic effects of ultraviolet light.

RESUMO Objetivo: Avaliar o efeito da aplicação da luz ultravioleta e riboflavina sobre ceratócitos da córnea humana in vitro. Métodos: Os ceratócitos foram obtidos a partir das rimas corneoesclerais remanescentes da trepanação de córneas previamente utilizadas em cirurgias de transplante de córnea e cultivadas em meio DMEM/F12 com 2% de FBS até atingir confluência. As culturas de células foram caracterizadas por imunofluorescência com os anticorpos K3 (marcador de células epiteliais), Thy-1 (marcador de fibroblasto) SMA (marcador de miofibroblasto) e Lumican (marcador de ceratócitos). Imunofluorescência também foi feita após o tratamento. As células do estroma da córnea foram cobertas com colágeno (200 µL e 500 µL) e 0,1% de riboflavina e exposta a luz UVA a 370 nm por 30 minutos. Após 24 horas, citotoxicidade foi determinada por ensaio de MTT e a viabilidade celular foi feita por Hoechst 33342/Iodeto de propideo. Resultados: As culturas de células atingiram confluência em aproximadamente 20 dias. Imunofluorescência apontou alta expressão para o marcador de ceratócitos (Lumican) e expressão negativa par os marcadores de células epiteliais (K3), fibroblasto (Thy-1) e miofibroblasto (α-SMA). Após o cross linking a análise de MTT mostrou baixa taxa de toxicidade e com a coloração de Hoechst 33342/Iodeto de propideo baixa taxa de apoptose e necrose respectivamente em todos os grupos que continham colágeno. Conclusão: As culturas de ceratócitos foram obtidas e caracterizadas por imunofluorescência através do marcador Lumican com sucesso. O ensaio de MTT e a coloração por Hoechst 33342 e iodeto de propídio, apresentaram maior índice de morte celular nos grupos que não continham colágeno, provando que protege as células contra os efeitos da luz UVA.

Influência de diferentes densidades de energia do laser de baixa intensidade em fibroblastos derivados da polpa de dentes decíduos / Influence of low-level laser with different energy densities on pulp fibroblasts from human primary teeth

O objetivo deste trabalho foi comparar os efeitos de diferentes densidades de energia e irradiâncias do Laser de Baixa Intensidade (LBI), variando em função do tempo de irradiação e potência, na viabilidade e proliferação de fibroblastos derivados da polpa de dentes decíduos humanos (HPF). HPF foram cultivados em DMEM e usados entre a 4ª e 8ª passagem. Os grupos foram divididos de acordo com diferentes densidades de energia, variando: Tempo de irradiação - Grupo I Ia (1,2 J/cm2 - 5 mW - 10 s), Ib (2,5 J/cm2 - 5 mW - 20 s), Ic (3,7 J/cm2 - 5 mW - 30 s), Id (5,0 J/cm2 - 5 mW - 40 s), e Ie (6,2 J/cm2 - 5 mW - 50 s); ou potência - Grupo II IIa (1,2 J/cm2 - 5 mW - 10 s), IIb (2,5 J/cm2 - 10 mW - 10 s), IIc (3,7 J/cm2 - 15 mW - 10 s), IId (5,0 J/cm2 - 20 mW - 10 s), e IIe (6,2 J/cm2 - 25 mW - 10 s). Células não irradiadas - cultivadas em condições nutricionais regulares - 10% Soro Fetal Bovino (SFB) (If e IIf) e células não irradiadas - cultivadas em déficit nutricional - 1% SFB (Ig e IIg), foram consideradas controles positivos e negativos, respectivamente. A viabilidade e proliferação celular foram avaliadas, repesctivamente, pelas técnicas MTT e Cristal violeta (CV), nos períodos de 24, 48 e 72 horas após a irradiação. Os dados obtidos foram submetidos à análise estatística por ANOVA 2 critérios, seguido pelo teste de Tukey (P<0,05). No ensaio MTT, os controles negativos, Ig e IIg, apresentaram significativamente menor viabilidade em relação aos correspondentes grupos experimentais: IIa e IIb, 24 horas após a irradiação; Ia, Ib, Ie, If e IIf no período de 48 horas; e Ib-If, assim como, IIa-IIf após 72 horas. Nos diferentes períodos de avaliação do ensaio CV, todos os grupos, exceto Ie, IIe e If, exibiram significativamente maior proliferação em comparação aos respectivos controles negativos. Dentro de um mesmo grupo nos diferentes períodos, os grupos If e IIe apresentaram menor viabilidade durante o período de 24 horas em comparação ao período de 72 horas pelo ensaio MTT. Na avaliação intragrupos, o ensaio CV revelou menor proliferação no período de 24 horas em comparação aos períodos de 48 e 72 horas, independente do grupo avaliado. Os diferentes protocolos de irradiação, grupos I e II, não apresentaram diferença estatisticamente significativa na viabilidade e proliferação celular entre densidades de energia iguais com irradiâncias diferentes durante os períodos avaliados. De acordo com os resultados obtidos, as diferentes densidades de energia e irradiâncias propostas não prejudicaram a viabilidade e proliferação de fibroblastos pulpares de dentes decíduos humanos. A variação do protocolo de irradiação LBI, em função do tempo ou da potência, não interferiram nas respostas celulares após a aplicação da mesma densidade de energia com irradiâncias diferentes.(AU)

The aim of this study was to compare the effects of Low-level laser (LLL) with different energy densities and irradiances, varying according to the irradiation time and power, on cell viability and proliferation of pulp fibloblasts from human primary teeth (HPF). HPF were culture in DMEM and used between 4th and 8th passages. Groups were divided according to different energy densities, varying: Time of irradiation Ia (1.2 J/cm2 - 5 mW - 10 s), Ib (2.5 J/cm2 - 5 mW - 20 s), Ic (3.7 J/cm2 - 5 mW - 30 s), Id (5.0 J/cm2 - 5 mW - 40 s), and Ie (6.2 J/cm2 - 5 mW - 50 s); or output power - Grupo II IIa (1.2 J/cm2 - 5 mW - 10 s), IIb (2.5 J/cm2 - 10 mW - 10 s), IIc (3.7 J/cm2 - 15 mW - 10 s), IId (5.0 J/cm2 - 20 mW - 10 s), e IIe (6.2 J/cm2 - 25 mW - 10 s). Non-irradiated cells - grown in regular nutritional conditions - 10% Fetal Bovine Serum (FSB) (If and IIf) and non-irradiated cells - grown in nutritional deficit - 1% FBS (Ig and IIg) were considered positive and negative controls, respectively. Cell viability and proliferation were respectively assessed through MTT and Crystal violet (CV) assays at 24, 48 and 72h after irradiation. Data were submitted to statistical analysis by ANOVA 2 criteria, followed by Tukey test (P<0.05). In the MTT assay, the negative controls, Ig and IIg, showed significantly lower viability in relation to the corresponding groups: IIa and IIb 24 hours after irradiation; Ia, Ib, Ie, If and IIf at 48 hours period; and Ib-If, as IIa-IIf, after 72 hours. At different periods of evaluation of CV assay, all groups, except Ie, IIe and If, exhibited significantly higher proliferation compared to the respective negative controls. Within the same group at different periods, groups If and IIe showed lower viability during 24 hours compared to 72 hours period by MTT assay. In the intragroup evaluation, CV assay revealed lower proliferation at 24 hours compared to 48 and 72 hours periods, regardless of the evaluated group. Different irradiation protocols, groups I and II, showed no statistically significant differences on cell viability and proliferation among equals energy densities with different irradiances at the evaluated periods. According to these findings, different LLL energy densities and irradiances proposed did not impair viability and proliferation of pulp fibloblasts from human primary teeth. The variation of the LLL irradiation protocol, by the time or power, did not interfere in cellular responses after the application of the same energy density with different irradiances.(AU)

Low-intensity laser phototherapy enhances the proliferation of dental pulp stem cells under nutritional deficiency

Abstract Dental trauma in immature permanent teeth can damage pulp vascularization, which leads to necrosis and cessation of apexogenesis. Studies on tissue engineering using stem cells from human exfoliated deciduous teeth (SHEDs) have yielded promising results. Laser phototherapy (LPT) is able to influence the proliferation and differentiation of these cells, which could improve tissue engineering. SHEDs (eighth passage) were seeded into 96-well culture plates (103 cells/well) and were grown in culture medium supplemented with 15% defined fetal bovine serum (FBS) for 12 h. After determining the appropriate nutrition deficiency status (5% FBS), the cells were assigned into four groups: 1) G1 - 15% FBS (positive control); 2) G2 - 5% FBS (negative control); 3) G3 - 5% FBS+LPT 3 J/cm2; and 4) G4 - 5% FBS+LPT 5 J/cm2. For the LPT groups, two laser irradiations at 6 h intervals were performed using a continuous wave InGaAlP diode laser (660 nm, with a spot size of 0.028 cm2, 10 mW) in punctual and contact mode. Cell viability was assessed via an MTT reduction assay immediately after the second laser irradiation (0 h) and 24, 48, and 72 h later. We found that G3 and G4 presented a significantly higher cell growth rate when compared with G2 (p < 0.01). Moreover, G4 exhibited a similar cell growth rate as G1 throughout the entire experiment (p > 0.05). These findings indicate that LPT with 5 J/cm2 can enhance the growth of SHEDs during situations of nutritional deficiency. Therefore, LPT could be a valuable adjunct treatment in tissue engineering when using stem cells derived from the dental pulp of primary teeth.

The effect of elemene on lung adenocarcinoma A549 cell radiosensitivity and elucidation of its mechanism

OBJECTIVE: To investigate the effect of elemene on the radiosensitivity of A549 cells and its possible molecular mechanism. METHODS: Apoptosis of A549 cells was detected by flow cytometry and fluorescence microscopy. The effect of double-strand break (DSB) damage repair in A549 cells was evaluated using the neutral comet assay. Protein expression levels were detected using western blotting, and the correlation between protein levels was analyzed. RESULTS: Elemene exhibited a radiosensitizing effect on A549 cells. The level of apoptosis induced by elemene combined with radiation was significantly greater (p<0.01) than that elicited by either radiation or elemene alone. Following radiation and subsequent repair for 24 h, the tail intensity of A549 cells treated with a combination of elemene and radiation was greater than that of cells treated with either elemene or radiation alone (p<0.01). This result indicates that elemene inhibits cellular DSB repair. Both elemene combined with radiation and radiation alone decreased the protein expression of DNA-PKcs and Bcl-2 compared to elemene alone (p<0.01), while p53 protein expression was increased (p<0.01). A negative correlation was observed between DNA-PKcs and p53 expression (r=−0.569, p=0.040), while a positive correlation was found between DNA-PKcs and Bcl-2 expression (r=0.755, p=0.012). CONCLUSIONS: Elemene exhibits a radiosensitizing effect on A549 cells, and its underlying molecular mechanism of action may be related to the downregulation of DNA-PKcs gene expression. .

El Estado, la espera y la dominación política en los sectores populares: entrevista al sociólogo Javier Auyero / The State, waiting and political domination among the poor: interview with the sociologist Javier Auyero

La extensa obra de Javier Auyero sobre los sectores populares en América Latina inquieta por su complejidad sociológica y política. Alejada de los lugares comunes sobre cómo viven, sufren y se relacionan los habitantes de los márgenes de nuestras ciudades, su programa de veinte años de investigación aborda las consecuencias del neoliberalismo en la marginalidad urbana. Por la publicación de su último libro, Pacientes del Estado (2013), Salud Colectiva lo invita a reflexionar sobre las conexiones, no siempre observadas, entre la espera y la dominación política en oficinas estatales, escuelas y hospitales. Su estrategia etnográfica le permite ingresar sin prejuicios a un universo social atravesado por posicionamientos sociales polarizantes. En los encuentros cotidianos de los pobres con diversas formas de poder estatal, afirma, se reproducen prácticas -no todas ellas igualmente conscientes y planificadas- que imparten educación política y culminan convirtiendo a quienes deberían ser ciudadanos con derechos en pacientes del Estado.

The extensive work of Javier Auyero regarding the poor in Latin America is disturbing in its sociological and political complexity. Instead of falling into the commonplace explorations of how inhabitants at the margins of our cities live, suffer and relate, his twenty years of research have focused on the consequences of neoliberalism in urban marginality. In light of the publication of his last book Patients of the State (2013), Salud Colectiva invited Auyero to reflect on the connections, not always observed, between waiting and political domination in government offices, schools and hospitals. His ethnographic strategy allows him to enter without prejudices into a social universe marked by polarizing political positions. He affirms that in the everyday encounters of poor people with the diverse forms of state power, practices are reproduced - not all of which are equally conscious and planned - that impart a political education and end up turning those who should be citizens into patients of the State.

[A] logarithmic formula to describe the relationship between the increased radiosensitivity at low doses and the survival at 2 gray

Intrinsic radiosensitivity at doses used in radiotherapy is linked to hypersensitivity [HRS] and increased radio resistance [IRR] at low doses. The aim of this study was to explore this relationship. Survival curves for 18 human tumour cell lines were analysed, using two models to fit the data points in order to extract the necessary parameters relevant for this study. The IRR ratio alpha s/alpha r versus the survival at 2 gray [Gy] can be described by a logarithmic relation which leads to a series of straight lines. The relationship obtained implies that there is a direct link between HRS/IRR and survival at clinically relevant doses of 2 Gy

Efeito dos laseres de baixa intensidade na proliferação e diferenciação de osteoblastos humanos / Low level laser effects in proliferation and differentiation of human osteoblasts

Dentre os vários compostos utilizados na pesquisa e na terapia de doenças osteo-degenerativas, a fototerapia com laseres de baixa potência (LLLT) e os diodos emissores de luz (LEDs) vem sendo investigada com o intuito de avaliar seus efeitos no metabolismo ósseo. Estes, que possuem comprimentos de ondas específicos, atuam na biomodulação das células, funcionando como um agente terapêutico, reequilibrando e normalizando a sua atividade. No entanto, pouco se sabe sobre o efeito dos diferentes espectros na proliferação e diferenciação de osteoblastos humanos, bem como seus efeitos no metabolismo celular como a síntese e a ativação de proteínas sinalizadoras envolvidas nesses processos. Diante disso, o objetivo deste trabalho foi avaliar, comparativamente, a influência da fototerapia com LLLT e LED na proliferação e diferenciação de osteoblastos humanos. Além disso, investigamos o envolvimento da ativação da via de sinalização ERK1,2 nestas respostas, utilizando o seu inibidor específico e/ou avaliando a sua ativação durante a proliferação e após fototerapia. Para esse estudo, osteoblastos humanos (HOAL) foram cultivados em meio de cultura DMEM suplementado com 10% de soro fetal bovino (SFB) e incubados em estufa de CO2. As células foram irradiadas pontualmente com os laseres vermelho (660nm), infravermelho (780nm) e LED (637nm), nas doses de 10, 20 e 50 J/cm2 na potência de 40mW, após adesão celular. Após 24, 48, e 72 horas foram realizados os ensaios de redução do MTT (brometo de 3-(4,5-dimetiltiazol-2-yl)-2,5- difeniltetrazólio) e cristal violeta (CV) para avaliar a viabilidade das células e após 72 horas foi realizada a análise da proliferação por citometria de fluxo nos quais os resultados sugerem aumento de células viáveis ou proliferação quando estimuladas pelos diferentes espectros. Após a verificação do efeito positivo dos laseres e LED na viabilidade e/ou proliferação, foi realizada a análise da ativação da proteína intracelular ERK...

Among the various compounds used in research and bone degenerative diseases therapy, phototherapy with low level laser (LLLT) and light emitting diodes (LEDs) has been investigated in order to evaluate its effects on bone metabolism. Those, who have specific wavelengths, act in biomodulation cells functioning as a therapeutic agent, rebalancing and normalizing their activity. However, little is known about the effect of the different spectra in the proliferation and differentiation of human osteoblasts and their effects on cellular metabolism as well as the synthesis and activation of signaling proteins involved in these processes. Therefore, the aim of this study was to compare the influence of LLLT and LED phototherapy in the proliferation and differentiation of human osteoblasts. In addition, we investigated the involvement of activation of ERK1,2 signaling pathway these responses using its specific inhibitor and/or evaluating their activation during the proliferation and after phototherapy. For this study, human osteoblasts (HOAL) were cultured in DMEM culture medium supplemented with 10 % fetal bovine serum (FBS) and incubated in CO2 incubator . Cells were irradiated with punctual red lasers (660nm), infrared (780nm) and LED (637nm) at doses of 10, 20 and 50 J/cm2 in power 40mW, after cell adhesion. After 24, 48, and 72 hours, MTT assay (- (4,5- dimethylthiazol-2- yl) -2,5 - diphenyltetrazolium bromide 3 ) and violet crystal (CV) were performed to assess the viability of cells and after 72 hours, was performed of proliferation analysis by flow cytometry. The results suggest an increase in viable and proliferation of cells when stimulated by different spectra. After checking the positive effect of lasers and LED viability and/or proliferation, analysis of ERK activation of intracellular protein by western blotting using a specific antibody was performed 10 minutes after the spot irradiation. We show that irradiation of HOAL cells with LLLT at a dose...

Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation.

Quantitative Evaluation of Viability- and Apoptosis-Related Genes in Ascaris suum Eggs under Different Culture-Temperature Conditions

Ascaris suum eggs are inactivated by composting conditions; however, it is difficult to find functional changes in heat-treated A. suum eggs. Here, unembryonated A. suum eggs were incubated at 20degrees C, 50degrees C, and 70degrees C in vitro, and the gene expression levels related to viability, such as eukaryotic translation initiation factor 4E (IF4E), phosphofructokinase 1 (PFK1), and thioredoxin 1 (TRX1), and to apoptosis, such as apoptosis-inducing factor 1 (AIF1) and cell death protein 6 (CDP6), were evaluated by real-time quantitative RT-PCR. No prominent morphological alterations were noted in the eggs at 20degrees C until day 10. In contrast, the eggs developed rapidly, and embryonated eggs and hatched larvae began to die, starting on day 2 at 50degrees C and day 1 at 70degrees C. At 20degrees C, IF4E, PFK1, and TRX1 mRNA expression was significantly increased from days 2-4; however, AIF1 and CDP6 mRNA expression was not changed significantly. IF4E, PFK1, and TRX1 mRNA expression was markedly decreased from day 2 at 50degrees C and 70degrees C, whereas AIF1 and CDP6 mRNA expression was significantly increased. The expressions of HSP70 and HSP90 were detected for 9-10 days at 20degrees C, for 3-5 days at 50degrees C, and for 2 days at 70degrees C. Taken together, incremental heat increases were associated with the rapid development of A. suum eggs, decreased expression of genes related to viability, and earlier expression of apoptosis-related genes, and finally these changes of viability- and apoptosis-related genes of A. suum eggs were associated with survival of the eggs under temperature stress.

Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led

OBJECTIVE: Applications of resin luting agents and high-power light-emitting diodes (LED) light-curing units (LCUs) have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs) polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. MATERIAL AND METHODS: Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50 percent of the manufacturer's recommended exposure time) and 40 s (100 percent exposure time). After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x10(4) per well) and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. RESULTS: Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion) reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples) followed by Rely X Unicem and Rely X ARC (90.81 percent, 88.90 percent, and 83.11 percent, respectively). For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively). CONCLUSION: The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical performance.

Mechanisms of Apoptosis on Human Lens Epithelium after Ultraviolet Light Exposure

PURPOSE: The purpose of this study is to understand the mechanism of apoptosis occurring on a cultured human lens epithelial cell line after exposure to ultraviolet (UV) light. We intended to confirm the presence of cellular toxicity and apoptosis and to reveal the roles of p53, caspase 3 and NOXA in these processes. METHODS: Cells were irradiated with an ultraviolet lamp. Cellular toxicity was measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Hoechst staining and fluorescent anti-caspase 3 antibodies were used for apoptosis investigation. The quantities of p53, caspase 3, and NOXA were measured by Western blotting for to investigate the apoptosis pathway. RESULTS: Cellular toxicity on the human lens epithelium markedly increased with time after UV exposure. On Hoechst staining, we found that apoptosis also remarkably increased after exposure to ultraviolet light, compared with a control group. In the immunochemical study using anti-caspase 3 antibodies, active caspase 3 significantly increased after exposure to ultraviolet light. On Western blotting, p53 decreased, while caspase 3 and NOXA increased. CONCLUSIONS: Exposure of cultured human lens epithelial cell lines to ultraviolet light induces apoptosis, which promotes the expression of NOXA and caspase 3 increases without increasing p53. This may suggest that UV induced apoptosis is caused by a p53-independent pathway in human lens epithelial cells.

Cytotoxicity of gamma-ray in rat immature hippocampal neurons

This in vitro study evaluated the detrimental effect of acute gamma (gamma)-irradiation on rat immature hippocampal neurons. Rat immature hippocampal neurons (0.5 day in vitro) were irradiated with 0~4 Gy gamma-rays. Cytotoxicity was analyzed using a lactate dehydrogenase release assay at 24 h after gamma-irradiation. Radiation-induced cytotoxicity in immature hippocampal neurons increased in a dose-dependent manner. Pre-treatments of pro-apoptotic caspase inhibitors and anti-oxidative substances significantly blocked gamma-irradiation-induced cytotoxicity in immature hippocampal neurons. The results suggest that the caspase-dependent cytotoxicity of gamma-rays in immature hippocampal cultured neurons may be caused by oxidative stress.